QOB Circuit Breaker, Current Rating 40 Amps, Minimum Wire Size 8 AWG, Maximum Wire Size 2 AWG, 120/240 Volts, Single Pole QO (Plug-In) and QOB (Bolt-On) Circuit BreakersQwik-Open breakers are for use only with QO load centers, NQ and NQOD panelboards. QOB breakers are for use only with NQ or NQOD panelboards. Rated for aluminum and copper conductors.120/240VAC (1 and 2 pole: 120VAC, 3 pole: 240VAC) Visi-Trip indicator Standard and VH breakers are UL Listed as HACR type